A Cost Effective Way to Cut Smog

March 15, 2012

Rather than imposing enormously expensive new restrictions on American emissions of ozone, as the Environmental Protection Agency (EPA) has proposed, perhaps it is time to look across the Pacific for more cost-effective ways to clear the air. Indeed, while domestic causes of this hazardous haze have been declining, as much as 20 percent of California's smog may now be coming from Asia, say Julian Morris, vice president of research, and Adam Peshek, a research associate, at the Reason Foundation.

Since 1980, average levels of ozone, the main component of smog, have declined by 25 percent nationally according to the EPA.

Concentrations of ozone have now fallen so far that in many places they are close to background levels -- that is, the levels that would occur without any industry or vehicles.

Moreover, there is now evidence that a small but significant proportion of ozone on the West Coast of the United States comes from Asia.

A recent study published in the Journal of Geophysical Research showed that in spring, low pressure systems in Asia can cause ozone to rise two to six miles into the atmosphere, where it is blown across the Pacific by strong winds.

It is then pulled back down to ground-level by high pressure systems in the Northeastern Pacific.

The study found that Asian emissions contributed 8 to 15 parts per billion (ppb) of ozone in California during the spring of 2010 -- accounting for about half of the days the state was in non-compliance with EPA's threshold of 75 ppb.

The EPA had planned to ratchet down the limit to between 60 and 70 ppb. Given the proportion of ozone flowing over from Asia, some counties could have found themselves in breach of EPA rules even if they had no industry and no cars. President Obama scrapped the proposed rule last fall, but the EPA is currently conducting its regular five-year review of ozone, which could impose a lower level as early as 2013.

Additional regulations may cut emissions further, but would also drive up the cost of doing business in America. Moreover, to the extent that the ozone problem is now being imported from Asia, it might make sense to look at ways of encouraging China, Thailand, Vietnam and other culprit countries to reduce their emissions instead of focusing exclusively on domestic emissions.